Heat-insulating structure.



A. ,Pf LUNDIN,

HEAT INSULATING STRUCTURE. APPLIUATIONFILBD JUNE 24, 10913.

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, IVIl VI" ANDREAS LUNDIN, 0F NEW YORK, N. Y.

HEAT-NSULATING STRUCTURE.

Specification of Letters Patent. P.fttseglllitelill liliztll. 30, 1915.

Application filed .Tune 24, 1913. Serial No. 775,523.

of the borough of Queens, county of Queens,

city and State of New York, have invented an Improved Heat-Insulating Structure, of which the following is' a description in such full, clear, and exact terms as will enable any person skilled in the art to which it pertains to make and use the same. v

My invention relates to the construction of refrigerators or structures designed to prevent the transmission of heat to goods stored therein and which goods it is desired to keep in a cold or refrigerated condition. An example of such structures is to be found in the well known household refrigerator Esed for the preservation of foods and the 'ke. two essential elements are always to be found, to wit: a frame contributing the neeessary mechanical strength to the structure and a heat insulating means, which latter is usually such material as cork, in solid or granular form, fibrous materials, sawdust and similar substances. But in no instance in refrigerator construction known to me have these two effects, structural or mechanical strength and insulation, been found combined in a single, unitary element, with the possible exception of an ordinary pine wood box, and this is not fairly a refrigerator because its degree of heat insulation is negligible and for this reason noti/'within the purview of my invention.

I have discovered that a heat insulating structure such as that to which my invention relates may be constructed wholly of balsa wood, which single material or element combines the two functions above referred to, that is to say, the functions of furnishing the mechanical strength by which to hold the structure together permanently and of furnishing the insulation or non-heat-conducting effect necessary to refrigeration to a degree at least equal to the degree of insulation attained in the best constructed cork or fiber insulated refrigerators. In other words, according'to my invention, I build the heat insulating structure substantially of balsa wood and by this alone I make the structure strong and durable from a mechanical standpoint and give to it a degree of heat insulating capacity equal to or ex- Ordinarily in structures of this sort ceeding that afforded by the best form of cork or fiber packing in refrigerators of the usual construction. The balsa wood referred. to is found in tropical America. Its botanical nameis Uchroma Lagopus. It is a treev which grows to about the size of the North American pine. The wood is of extremely light weight and of very peculiar formation. It is composed almost exclusively of pith fibers running longitudinal and transversely and themselves made up of short barrelshaped cells with extremely thin walls which endow it with the power of heat insulation. which I have discvered. These fibers are closely interlaced and I have found them to be remarkably tough and elastic so that the wood possesses a mechanical strength approximating that of spruce or pine. When this wood 1s properly treated by a waterproofing compound it furnishes one of the best known heat insulating materials and its mechanical strength enables me to construct a heat insulator building or refrigerator exclusively of this wood and thereby combine in one element those functions which heretofore have been performed by two elements, to wit, the frame or supporting part p of the building and the refrigerating element of the cork, saw-dust, felt or other heat insulating material.

The accompanying drawings illustrate as an example the preferred manner of adapting my discovery to practical construction of a household refrigerator.

In these drawings: Figure 1 is a sectional plan on the line 1 1 of Fig. 2 and Fig. 2 is a fragmentary elevation of the refrigerator.

Referring to the drawings a indicates the walls of the refrigerator which are formed of balsa wood of suitable thickness either integral or formed of several layers or laminations, these walls being mortier into corner posts b also of balsa wood, which posts extend down to form the legs or supports. These two elements a and b, or their equivalents arranged in any convenient way, constitute the whole of the essentials of the4 I By their means the refrigerator structure. is given mechanical or structural strength and owing to the heat insulation properties of the balsa wood the refrigerator is given a degree of nonheat conductivity equal to that of any form of heat insulation heretofore known. If desired the refrigerator necessary longibers. into Sheets may have a lining c of any kind of sheet material which serves only to provide a sanitary surface for contact with the'food orother substance contained in the refrig? erator.

To provide a desirable exterior finish for degree .of yfinish or ornamentation. The

y' `Walls a and posts b (and such other balsa vrWood parts as maybe employed) are surface treated or coated by any suitable v method for the purpose of closing thehair lwhereby the structural cells and preventing absorption of moisture thereby.

Having thus described the invention, what claim as new and desire to secure by Letters 'Patent of the United States is z- As a new article of manufacture, a substantially air-tight container, constructed to contain perishable matter and preserve the same at a low temperature by means of a refrigerant contained therein, all the walls of said container being composed substan tially entirely of Waterproofed balsa wood,

strength and heat insulating effects are united in a single element.

In testimony whereof I have hereunto signed my name in the presence of two witnesses. I

ANDREAS P. LUNDIN.

Witnesses:

ARTHUR VEHLOW, SYDNEY H. GIELLERUP. 

